I am guessing the I have the same noise you do. Sounds like something spinning is ratteling around behind the A/C Heat Controller. Seems to happen on cold mornings so far....even before I get the key in the ignition. Once I get it all heated up inside the noise goes away.

What is the "sampler fan"? Can you get replacements for less than a million bux?

__________________
2002 X5 3.0i